


Actus Reus “The Guilty Act”

by AddisonAddek



Category: Grey’s Anatomy
Genre: Addison and Derek and Mark, Angst, Best Friends, Bi-curious, Blow Jobs, Brokeback mountain - Freeform, Brother/Brother Incest, Cheating, Childhood Trauma, Depression, Despair, F/M, Family, First Time Blow Jobs, Fluff and Angst, Gay Sex, Gen, Hand Jobs, Hurt and comfort, Infidelity, Loneliness, M/M, Maddek - Freeform, Marital Issues, Mark is confused, Marriage, Masturbation, Mutism, Mutual Masturbation, Non-Explicit Sex, Oaths & Vows, Post-Traumatic Stress Disorder - PTSD, Pre series, Pseudo-Incest, Public Hand Jobs, Public Masturbation, Sex, Sexual Content, Smut, Trauma, addek, best friend’s wife, grey’s anatomy - Freeform, m/m - Freeform, maddison - Freeform, mature - Freeform, murdered parent, mute Derek Shepherd, non descriptive anal sex
Language: English
Status: Completed
Published: 2020-05-23
Updated: 2020-05-23
Packaged: 2020-08-12 00:20:36
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,507
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20162569
Author URL: https://archiveofourown.org/users/AddisonAddek/pseuds/AddisonAddek
Summary: Mark Sloan kisses his best friend's wife like he's been doing it his entire life.A Maddek (ish, not really, more like Addison/Mark and Derek/Mark) One Shot.Common denominator = MarkAddison/Derek/MarkAddison/MarkAddison/DerekDerek/Mark#Maddek #Maddison #Addek #Derk? #Marek?COMPLETEDUpdated : 23/05/2020Made more changes. Added a little more flare.Enjoy





	Actus Reus “The Guilty Act”

**Author's Note:**

> I made a few changes to this story from when I first posted it since there was something about it that I wanted to explore a bit further.
> 
> Enjoy this one-shot of the trio, Maddek, that popped into my deprived mind while I was studying at the library yesterday.
> 
> This is very fictional. Very unusual. Very unrealistic. Very imaginative with a hint of Brokeback Mountain, if you know what I mean ;) It's different, I guess, but my brain wanted to write this.
> 
> Enjoy.  
Leave a comment.

* * *

**Actus Reus**

_"The Guilty Act"_

* * *

When you kiss Addison, it's _Derek_ that you taste.

It's there, clinging to the wet softness of her tongue, the tangy hint of weed and weakness and wallowing in self-pity that bites into your soul the way her teeth sinks into your bottom lip. It hurts a little and you would be surprised if she were anyone else but Addison, however, it's all pain when it comes to her. Always. Some pain, some pleasure, but you would be damned to claim that she isn't the most beautiful sin you've ever seen.

But the bitter taste of iron masks the remnants of your best friend and you just open your mouth wider and let her in. For a moment, you forget the girl you're kissing belongs to the person you care about and almost love the most in the entire world. Because he's family, you tell yourself. For a moment, you think it really is Derek's mouth pressing open and wet against yours, licking you clean and filling you up.

Except the hair twining between your fingers is too long and too soft, and her bones poke almost painfully through the thin coating of skin and satin, and when her jaw scrapes against yours, it's all smooth silkiness and doesn't prickle and burn your skin.

You blink, just once, and when your eyes focus again, they're locked on hers and she's watching you through a haze of escape. She looks like herself, all sharp angles and dark shadows, prim and proper - almost, _just_ _almost_ \- but you see the same cage reflected in her eyes.

The car is silent and all that comes with it, all the reasons Derek should be with her and none of the reasons he wants to be with her. It creeps up Fifth Avenue, and the harsh florescent lights paints cruel patterns across Addison's pale skin, and she looks dingy and used up, like she's been chewed up and spat back out. You've seen that look before, every time Derek shows up drunk and desperate at your front door after a heated argument with no one other than Addison, his wife.

You don't understand what's going on. You don't, but, really, you're the same cocky bastard you were yesterday, so you actually do.

You only kiss her harder and slip your hands under the hem of her dress the way you used to slip your hands under the hem of Derek's sweater when he'd fall into your arms and you'd make it all better.

Derek found you near the pond you both used to hang out at to feed the ducks. You don't understand why he always drops to his knees next to you and buries his face into your neck shakily. But you now cling to Addison the same way Derek clung to you that mid-afternoon and you remember him whimpering into your skin, his body melting into yours bonelessly.

It made you shiver. The way he practically tried to climb into your skin. He hadn't said a word in six months by then, you recalled.

You feel her hands travelling over your back and arms and the flat planes of your chest and you breathe quickly and shallowly as Derek did. His heart was thudding against his ribs hard enough that you could feel it through your shirt.

You could still feel it, sometimes, when you would just wish hard enough.

You never said anything to him, you never asked why; you don't think you could have handled the answer so you turned a blind eye and did what you think he wanted.

You didn't mind; you liked making him feel better.

When she pulls back to look in your eyes, you don't ask the question again because you know what to do, you know what she's going to say. You will still do it either way.

_I want you._

You know how to do it.

You're **_twelve-years-old_** and the store Mr. Shepherd spent almost every dime on hasn't break-even in months and had spent the entire night venting out on Derek's mom, arguing, and Derek has shown up at your doorstep crying and broken and convinced that his life is over.

So, you take him upstairs to your room - your dad isn't home, never is, just the housekeeper who you suspected knew what was going on upstairs.

Nothing really, because by then, all you knew was how to kiss.

You can taste the same fears in the mouth singeing yours now. Your fingers move across her skin and they press, press, gently, right where her shoulder meets her neck. When she moans into your mouth, you can see the same ecstasy moving across Derek's preteen face.

You kiss her and taste him and makes her forget.

* * *

Addison is more brittle than Derek, and when your fingers skim over her bare skin, the pure lace, you don't want to press too hard, press too close, because you're afraid if she opens her eyes and looks – really, really looks – she'll realise she's clinging to the wrong blue-eyed boy.

You're not ready to lose her, not quite yet, not when she feels different and familiar all at once and it's confusing and just not at all, not when you can taste everything you can't have with every flick of her tongue against yours.

Your hands move higher, over the hot skin of her thighs, and slip between them, caught between slick, wet heat and the coarse fabric of your pants. You're hard and tight all over and when you flick your wrist, just the tiniest bit, she whimpers a little at the back of her throat, red lips intact and open, and her hips settles over yours, softness against hardness.

You groan into her hair and you do it again, and again, and she's moaning again and again and it's delicate and feminine and there's nothing hard about it.

Her fingers slowly undoes the first few buttons of your shirt, hand delving at the zipper of your pants and you're _**sixteen-years-old**_ again, and you have had too much to drink to walk in a straight line, let alone get out of your jeans, and Derek's hands tremble a bit from too much Ketle One as they close over the zipper and pull tight denim down your knees. It was awkward in its own way when the uncertain hands landed on your lap; though you suspected it was coming, the strange sensation of hands that weren't your own was surprising but not unwelcome.

Her fingers are long and thin, and the nails click against the metal of the zipper as she slides it down and slips her hands into the ripple of curls. You half expect calluses from long practices of the saxophone, and while the fingers wrapping around you are smooth and soft, they shake slightly in the darkness, too.

When you kiss her again, inhaling deeply, shakily, you're the one to close your eyes and escape, focusing on Addison, just Addison and not Derek.

_No. Never Derek._

* * *

You flick your wrist again and it's hotter and wetter and tighter than before. She's ready, more ready than she's ever been, and you know it's not like any other time, and any other woman. _It's Satan._ You've never had a thing for redheads, and you've never been one to keep secrets.

When your pants hit your ankles and her dress is rucked up over her stomach, it's about anything but anyone's friend.

_Best friend._

You tell yourself it has nothing to do with anyone's best friend.

_Your best friend._

You've never been anyone's first time before and so hasn't she but you can't stop watching the look in her eyes. So innocent and vulnerable. Not like the Satan you've come to love. It's dark as the car climbs north, so dark you can't tell if they're green or if they're blue. They shift and change with every block you cross and you watch them water with pain and narrow with concentration, and round with wonder as she shifts her hips just a tiny bit and a groan hisses between your lips as your eyes slide towards the back of your head.

When you open your eyes again there's something sparking in hers, and you don't recognise how alive they suddenly seem. A smirk plays across her lips in a smile that's nothing but wicked and depraved, it doesn't matter how good she looks falling out of her dress or the way her full lips part to form a perfect circle or how much you like the way her perfume catches the air and clings, because she's the devil incarnate, and she shifts her hips again, and again, and you're no longer the one with the experience.

Red lips moves along your jawbone, barely touching, barely there, barely Addison, like the whisper of the devil to man.

You're _**fifteen-years-old**_ and Derek's asking what it's like, and you laugh in his face because the last thing you can ever see happening is any girl or anyone for that matter wanting and willing to have sex with a boy who has hair for a birds nest, acne, and weighs 130 pounds. He asks again and you try to explain, but your words catch in your throat because the look in his eyes is so dead and blank it takes your breath away.

So, you give him what he wants, your hands starting at his chest and stroking down to his ribs and belly; your fingertips pressing just slightly harder in all the right places. Derek breathes are heavy, struggling to keep himself still and calm while you stroke his stomach and wait for him to calm down - you know he's torn between wanting, needing your touch and being disgusted by the contact, being afraid of how _right_ this _wrong_ feels because you're not a girl.

You both know that boys aren't supposed to do this with boys. But you don't really care what society has to say.

Derek is different, though, because you don't have an overbearing Catholic mother - in fact, you don't have a mother anymore.

You feel the exact moment Derek wins his internal debate. But you feel the moan more than you hear it, it vibrates against your lips as his tongue presses into your mouth. Your heart pounds as your hands slip lower, finding the hardened bulge in his pants surprising and pleasing.

Nerves causes you to fumble when you release the string holding his pants up and slips them down to free him from its confines. You gently brush your fingers over it in acceptance before letting your fingers gently touch the hardened length.

Derek's moan is audible this time, his mouth releasing you to suck at your throat, one of his hands pulling you and turning you onto your stomach and you feel his arousal against your cheeks.

Your mind catches up that you're really doing this. Derek is really going to _fuck_ you and you don't know what to think. It's your first time with a boy, any boy, let alone one that's your best friend and brother. Also, you heard from an older boy at school that it's going to hurt like shit.

No pun intended.

You feel like a puppet when he jerks your hips forward, align you with him, all wooden and taut strings. You crane your neck to press your lips to Derek's dry ones, and you taste self-doubt, self-hatred and self-destruction there.

And you now see how that was the inception of how you see yourself.

You're so scared and it's not for the impending pain. But you're trusting him, and he's trusting you. It's a mutual understanding between the two of you that out of everyone in the world, all the bad; whatever it is between you is good.

* * *

You struggle to catch your breath as she shifts again and your eyes round at the pulsing life glinting in hers.

Laughter rings in your ears and it's hers, because she sees the look in your eyes, and she takes advantage of the moment to choose the pace and push you back against slick leather and kiss you so hard you forget how to breathe. Heart presses against chest, like the cruel trail of liquid fire made over the weeping earth.

The first time it really happened was when you both were _**thirteen-years-old**_.

You just turned, actually. You're a few months younger than Derek and Addison. You stare up and into Addison's eyes and the saying is correct - the eyes are the window to the soul because they're cold, deathly sad and desperate but her body and smile says otherwise.

All you want is for her to be happy. You try and try; all you do is try to cheer them up, but they never are, never will. Your efforts are in vain and you can't seem to figure out why.

They don't ever notice your efforts.

They don't ever see how much you care and love them. They're _your_ family - your _only_ family because no one wanted you. Not your mother, nor your father, and you don't have grandparents or cousins or aunts and uncles. But if you do, you've never met them.

You remembered every Monday morning your school used to play the National Anthem and you would all stand and sing before first period start. You don't know if schools still does it, but you did every Monday as a kid.

"_Sing, Derek!_" One of the boys yelled one morning, shoving at his shoulder and you almost jumped over the desk to teach him a lesson but your teacher stopped you before you could.

“Mark, don’t.” The teacher knew you were protective of Derek, so they were always ready for you and your temper.

The boy was sent to see the headmaster.

It had already been a little over a month since Mr. Shepherd had been murdered and Derek had stopped talking altogether.

He hadn't seen a therapist yet, even though teachers at school, CPS were even called in, were telling his mom that he ought to.

_It's not normal._

_Children who are predisposed to social anxiety - when faced with trauma, like the death of a parent, are more vulnerable to conditions such as post-traumatic mutism..._

Mrs. Shepherd just sighed, you were there too at the other side of the principal's office with Derek, said that she'd give it another week before taking him to a see therapist.

And you wondered where she's ever going to get the money to do just that since the store had closed down and Mr. Shepherd is ... _gone_.

You remembered telling your dad about it and you remembered Mrs. Shepherd in tears a week later and you remembered your dad telling you years later that it wasn't because she didn't have the money to take Derek to see a psychiatrist but because she didn't understand why Derek was doing that to her.

Derek didn't talk for over a year and it was this fault.

Addison is scratching at your back in an attempt to make you move faster, before deciding to just press up and roll both of you over.

You went willingly, laying under her as she flatten herself against you and move at her own pace. The new angle has her gasping against your neck, biting down on the soft skin there until you are the one gasping for air.

"You don't have to hide it from me, Derek." You admit quietly as you both sit in the dirt. Your best friend seems calmed, his eyes shining slightly when the ducks come closer.

You know how it feels to lose a parent.

"I miss her. My mother." ... _though I'm still angry that she killed herself and left me._

The words nearly tumbles out of your mouth, and you flinch at how they sound. You haven't talked about your mother since she died seven years ago.

Derek's eyebrows go up, he knows it too and it's the first genuine expression you had ever seen him make in over a week. And then his eyes turn to regard you curiously. They're the eyes of Derek Shepherd, the boy that's hidden behind the detachment and numbness.

You blush hotly, breaking the eye contact to observe the birds waiting for more bread.

Time stops when Derek carefully reaches out and touch your cheek, turning your face back to look at him again. Wide eyed, you don't resist, too stunned and pleased by the unexpected contact to risk frightening him.

The hand brushes down your cheek to your neck and shoulders, and you openly stare in fascination at the look of pure ... something on Derek's 's face. You move slowly, reaching your own hand up to mirror the action. Derek flinches impulsively, the air rushing out of his mouth in a huff before he forces himself still. Eyes scrunched up, he allows your curious fingers to follow the same path his own had; his eyes fluttering open when your hand hesitates.

Derek's hand is frozen on your shoulder, his other grips at his own hip tightly - nearly in a vice. At a loss, you clear your throat. "Do you want me to ... to _touch_?"

Your tongue twines around hers again and you taste a breakup on her tongue. When your eyes lock with hers, the streetlights show only ocean staring back at you. When your fingers dig into the flesh of her hips and you pull her closer, sink into her deeper, the only person on your mind is exactly who she is.

_Your best friend's wife._

"I know it hurts. And it is never going to stop hurting. But it will get easier, I promise. I want you to know that I understand what you're going through, Derek," and the words causes the dam to break, then.

Your best friend makes a quiet whine and lurches forward to crush your lips together roughly. You gasp in pain as teeth clashes and his hands clutches at your face to fuse them together.

It was an inexperienced kiss of a _**thirteen-year-old**_.

It was messy and violent; needy and full of despair and understanding and shame.

You didn't resist the assault on your mouth, moving your lips as you tried to keep up with the brutal pace.

But it's over far too quickly.

When Derek pulls back, he smiles a small, haunted smile at you and you return it.

You return it because you feel that same smile inside your soul.

* * *

The first time Derek actually _actually_ touched you - well, he did more than just touched you that afternoon - you were three months to _**fourteen**_ while he had just turned **_fourteen_**. It was his birthday but there were no birthday celebration, no cake, no presents, you don't think anyone had even greeted him, but you did and bought him a present anyway.

You guys went to the pond with a pocket full of bread and Derek brought his only present with him to open. It was the entire Superman comic book collection and by the way he smiled at you, you knew he liked it.

The sentiment was touching, beautiful in a way not many things in life are.

Derek responded by kissing you, more gentle than ever before. You carefully took the box of comics from his hands and put it down for safe keeping and kissed him back while his hands pushed you onto the damp grass, as they roam eagerly down your chest.

"This is nice," you encouraged against the soft lips pressing yours open, and you felt the thin line of his lips curl up slightly at your words - another rare smile.

His hands were gentle and careful, fingers scratching over your nipples through your shirt. You groaned appreciatively because it was the first time anyone had touched you there, you didn't know it'd feel so good. And Derek grinned just slightly harder into you in response, then.

It was awkward because it was always you who did the touching, never Derek, never your best friend and you never questioned it. You do what Derek wants you to do because you enjoy it. But sometimes you would find yourself wondering how it'd feel if Derek was the one to swallow you down or jerk you off for a change.

You inhaled deeply and broke the kiss, keeping your eyes closed and focusing on Derek, just your best friend. "You ... you don't have to ... I can touch. I want to."

But he shook his head, a jerky and uncertain motion. The response seems to confuse him, his eyebrows pull together. You smiled soothingly though and pecked him on the lips again.

Derek crowded you against the grass with his arms locking you in between and you arched into him and he pressed his lines on your lines and you moan in reply when he started to move and move in a delicious rhythm.

"So good - oh, Derek - _fuck_ -" your voice was high as though a woman's and unfamiliar to your own ears and it was not something you would say, let alone think on your own - you had heard it from some of the women your dad would bring home at night when he thought you were asleep and you were really not.

The first time you walked out of your room to see what was going on, you didn’t understand what they were doing. The second, you did and it made you feel funny and ashamed at the same time. The third, the housekeeper caught you and you can only imagine now what she must have thought about the person you’d become.

Derek frowned, exhaling before he kissed you, longer and deeper this time. It was a strange thing, your mouths pressing, rough and also insistent. Your tongues felt like two matches striking, hot and charged. There was nothing tentative about it, no assurances or seduction needed.

Derek tasted like licorice and Fanta and you hate Fanta but you liked Derek’s version of it, so you licked him clean.

He was astride you and you knew it was because he was motivated to feel something, anything. It was not long before his tongue was down your throat, hand snaring your hair. Practice makes perfect because now he knew how to kiss you without making you bleed.

You've never felt anything like this before. You're so hard it's borderline painful.

"This is crazy," you managed to say and then there was a moment of hush, your breaths stilling, when Derek peeled down your boxers, exposing first the little thatch of your pubic hair, and then you to the fresh breeze of Westchester air and you were sure it was going to be over now.

He studied you like a mechanical piece. A tool. You both were similar in size, but you're slightly thicker and uncircumcised.

Derek took a moment to explore you, stroking the fold of skin and feeling the weight of you in his hand. He scooted downwards then, making clear of his intentions but he didn’t bother asking if you wanted to be sucked. He just bent at the waist, fist still coiled around you and his tongue darted out to taste.

You imagine you taste more or less the same. Salt and soap, the musk of fresh sweat.

He was starved for release, and you were too.

When you pulled him back up, you tasted yourself and he bit your neck, and you thought to yourself that it was not supposed to hurt more than pleasure, but at the same time, you thought of ways to explain to your father of the marks on your neck.

You could always say that it was a girl.

This was the one truth you can't tell him.

He was shaking, but you were too; his hand mirrors what yours does.

Derek's face was buried in your neck now, warm bursts of air against your sweaty skin caused you to shiver. He was hiding his face, and you wouldn't have it. You wanted to see Derek's face, watch what he looked like when things don't hurt him but feel only good. So you turned his head and nuzzled his throat, moving your hand quicker and quicker, your thumb brushing the head of his leaking member made him twitch and he craned his neck up to let you suck on his skin again.

His hand followed your lead, of what yours does, and you squeeze his tip gently, testing his reaction. You were rewarded with a sharp bite on your neck again, and the heat in your belly swelled and he was panting when you licked his ear. "You'll never be alone again. I'll be here whenever you need me," you whisper breathlessly, and that was all it takes.

Derek tensed against you and his breath caught in his throat when he came, the warm fluid wetting your hand.

You swore you heard Derek breathe your name but it was so quietly that you could be imagining it. And just the thought pushed you over the edge and you were coming with a moan, panting Derek's name directly into his ear.

Bonelessly, you both leaned on each other and inhaled the scent of your mingled release and sweat.

You didn't want to think it but you do sometimes think what would have happened if Derek's mother were to follow you here and find you both like this.

_Would she take him away from you forever?_

You nearly sobbed when Derek's hand timidly found your and held it tightly as if giving you an answer to your question.

You are family and you don't let family go.

* * *

Afterwards, you're both tired and she sprawls across your chest as the streetlights paint glimmering pictures across her skin. Her cheek is tucked into the curve of your throat, and she's warm and soft against you. You close your eyes as a light washes over your face and you're _**seventeen-years-old**_ and the morning sun is stinging your eyes and Derek's bare chest is pressed against yours. It's an awkward fit, and his nose jabs into your shoulder hard enough to bruise and you can't feel your left foot. Booze and regret cling to the air, but you breathe in and pull him closer because it isn't supposed to be.

When he leaves an hour later, it's with a sheepish grin and promises that it will never happen again. He keeps his word and starts dating Monica Geller (_aka Moni-cow)_ from the school band he's in a week later.

Addison says the same, but you know it's a lie when she tucks herself into the cradle of your arms and runs her foot up the length of your left calf. You pull her closer and hold her tighter and breathe her in. She smells like sex and satisfaction but nothing like regret.

You like the feeling.

You like _her_ too.

When you kiss her goodnight, it's only Addison that you taste

**Author's Note:**

> Please leave a comment. You can tell me how you feel about this nonsense if you’re not into Mark and Derek. But please be kind. :)


End file.
